Practical aspects of DFT-based frequency division multiplexing for data transmission

A practical implementation of digital frequency division multiplexing is presented. The design goals are the use of very few modulation schemes (two or three), uniform reliability across the subchannels, and the avoidance of peak power violation. The FTDM (Fourier transform division multiplexing) method is used to design signals for transmission. Data are encoded in the frequency domain, Fourier transformed to yield a real sequence, and a signal is transmitted whose sampled values, when inverse Fourier transformed, yield the original code. Spectral characteristics for the code are easily obtained because it is designed in the frequency domain.>